Two-temperature refrigerator



Patented Sept. 5, 1950 UNITED TWO-TEMPERATURE REFRIGERATOR Herman W. Kleist, Chicago, Ill., assignor to Dole Refrigerating Company, Chicago, Ill., a corporation of Illinois Application March 29, 1946, Serial p. 658,322

My invention relates to an improvement in refrigerators and has for one purpose to provide refrigeration means for a domestic refrigerator.

Another purpose is to provide an improved two temperature refrigerator.

Another purpose is to provide a refrigerator including improved freezing means for a low temperature storage space.

Other purposes will appear from time to time in the course of the specification and claim.

I illustrate the invention more or less diagrammatically in the accompanying drawings wherein;

Figure 1 is a vertical section;

Figure 2 is a section on the line 2-2 of Figure 1; and

Figure 3 isagplan view of the plate structure illustrated in the lower storage compartment of Figures 1 and 2. y

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings I illustrate in Figures 1 and 2 a conventional domestic refrigerator having side walls I and 2, a top wall 3, a bottom wall 4, a rear wall 5 and a horizontal partition wall i. These six walls together denne an upper storage chamber generally indicated as A and a lower storage chamber generally indicated as B. Each chamber has a forward opening or open side closed by insulated doors 1 and 8. It will be understood that the details of the insulation and of the walls do not of themselves form part of the present invention. I illustrate the compartments A and B as lined by any suitable sleeves 9 and In which may be of sheet metal or other suitable material. It will be understood that any suitable means may be employed for preventing heat transfer from the outside of the refrigerator to the sleeves 9 and I0. I may use for example a break in the material. Since such means do not of themselves form part of the invention, they are not indicated in the drawings, it being understood that any suitable type of insulated walls and door may be employed, to reduce heat transfer to a minimum.

The above described refrigerator housing may be mounted on or include a bottom structure having supporting legs I2 and side members I3 surrounding and defining a work chamber generally indicated as C. The work chamber C may be partially open, to permit free circulation of air.

In the work chamber I illustrate more or less diagrammatically a refrigerator unit including a base I5, a compressor I6, a motor I1, a condenser coil I8 and a. receiver I9. 20 indicates a low side or suction line extending to the low pressure side of the compressor I6. 2l is a high pressure duct extending from the compressor I6 to the condenser coil I8. 22 is a duct extending from the condenser coil I8 to the receiver I9, and 23 indicates a high pressure liquid line along which liquid refrigerant may be delivered from the receiver I9. The motor I1 may drive the compressor I8 for example through a belt 24. It will be understood that the unit thus described is indicated diagrammatically and any suitable means may be employed for receiving low pressure, evaporated refrigerant, and for delivering high pressure liquid refrigerant.

As means for withdrawing heat from the storage chambers A and B I illustrate a plurality of cold plates, preferably of the vacuum type. It will be understood that I prefer to employ the upper chamber A as a relative high temperature storage chamber where the temperature never reaches as low as the freezing temperature of Water. The chamber B is employed as a cold storage chamber in which materials may be frozen and stored in frozen condition. The temperature therein may be as low as 0 F. or lower.

In the lower chamber B I illustrate a battery or group of plates 25, herein shown as three in number and as arranged in parallel horizontal planes, the plates 25 being spaced apart sufficiently to provide adequate intermediate storage spaces The plates may be spaced for example by a plurality of supports 26 which may be positioned closely adjacent to the face of liner or sleeve I0, to provide a minimum loss of storage space. Each plate includes spaced horizontal walls 21 and 28, the walls 2B having surrounding circumferential flanges 29 which are sealed to the wall 21 to provide a space which is closed and which is preferably liquid and gas tight. In this space I employ any suitable evaporator coil 30. The space between the walls 21 and 28, and about the coil 30 is preferably partially lled with a suitable eutectic, to provide a holdover or storage feature. I may also employ any suitable pressure tting 3|, through which the interior of the plate may be partly evacuated in such fashion that the outside atmospheric pressure is effective to hold the walls 21 and 28 firmly against the coil 30, in adequate heat exchange relationship. It will also be seen that any spacing means or fins may be employed if necessary, although I nnd it advantageous, in general, to employ relative thin plates, with the walls 21 and 28 held, by the above mentioned pressure differential in intimate contact with the enclosed evaporator coil 30.

In the device as shown liquid refrigerant, at high pressure. is delivered through the duct 2l to any suitable pressure reducing device 32. It passes thence by the duct 33 to the lowest plate 2l, in the low temperature compartment B. After passing through the evaporator coil of the lowest plate, it ilows through the duct I4 to the evaporator coil of the intermediate plate. Thence after passing through the evaporator-coil of the intermediate plate it ows through the duct 35 to the coil of the top most plate 25. Thence the refrigerantilcws through a duct l5, which may be embedded through part of its length in the intermediate partition 5. It is used to deliver the refrigerant, not yet fully evaporated, to the top of a vertically disposed plate 21, which is shown as' dividing the upper compartment A into two divisions. The duct 3B delivers the refrigerant to the coil of the plate 31 and the refrigerant, after it has passed through the refrigerant coil of the plate 31, returns through. the suction duct 38 to the suction line 2l and thence back to the low side of the compressor i6. 1t will be understood that the plate 31 may be identical with the plates 25,

but I may find it preferable under some circumstances to omit the eutectic and to employ what I may call a, dry plate in the upper compartment A. At each side of the plate 31 I illustrate mesh or open work partitions 40 which space the stored material from actual contact with the faces or walls of the plate 35. 4I are any suitable and preferably removable shelves which may also be of open mesh material and which rest on any suitable supports l2 on the liner or sleeve 9 and corresponding supports 42 on the mesh walls 4I.

lIt will be realized that I may employ other plates than the vacuum plates herein shown, but I iind that vacuum plates of the type herein described are practical and adequate, and efficient in use.

It will be realized that, whereas, I have described and illustrated a.Y practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing.

The use and operation of my invention are as follows:

I illustrate a two-temperature cabinet in which readily applicable and readily removable cooling plates are employed. The parts are preferably so in proportion that the plates may be readily inserted through the apertures closed by the doors plates which cool the lower compartment B as a unit, connected by the side supports 25. I may provide any suitable means for controlling the temperature of the device, but I preferably do this by employing a thermally responsive member which responds to the temperature in the upper or warmer compartment. I illustrate, for example in Figure 2, a bulb 5l engaging or responsive to the temperature of the plate 31, which bulb. through a duct or tube 5i, is adapted to control any suitable switch means not shown, for closing any suitable motor circuit, when cooling is called for, and for breaking such motor circuit when the upper compartment has been sumciently cooled. The plates 2l of the lower compartment are preferably provided with the above described eutectic which provides e hold-over factor, and

insures against undesired increase in temperature. Since. when plate 31 calls for a refrigerant. the refrigerant must first pass through the plates 25, they are normally maintained at an adequately low temperature. If necessary a safety control may also be provided, including a bulb 6l in the lower compartment, and its associated tube 6|, extending to any suitable switch for closing the motor circuit when the lower compartment B reaches a pre-determined maximum temperature. Under normal circumstances this is unnecessary.

It will be understood that area of the plate 31 is sui'llcient to maintain an adequate low temperature in the upper compartment A without at any time reducing the walls of the plate 21 to a temperature suillciently low to cause frosting. The member 31, since it is a non-frosting cooling member, need never be defrosted.

In the use of the device, when the door 8 is opened for entry to the cold compartment B there -will be a tendency to form frost on the forward ends of the plates 25. I 11nd that by providing a substantial extension of the wall members 21 beyond the hollow part of the plates, I in eiect, provide a thin flange or iin, of substantial extension, beyond the eutectic filled hollow part of the plate. The temperature of the outer edge or part of the n rises in relation to the temperature of the plate body proper, with a substantial reduction of the tendency to frost at the outer edges of the plate. This makes it unnecessary to scrape any excess frost from the plate edges, which would otherwise be deposited by, or be drawn from, the inilowing outside warm air.

I claim:

In a refrigerator, an insulating housing including walls defining and surrounding two separate storage compartments, said storage compartments each having an access aperture, insulating door means adapted removably to close said access apertures, and means for maintaining an above freezing temperature in one said compartment and a below freezing temperature in the other said compartment, including a horizontal plate in the low temperature compartment and a vertical plate in the high temperature compartment, said vertical plate being positioned -to divide the high temperature compartment into two separate storage zones at opposite sides of said last named compartment, an air pervious partition closely adjacent each side of said vertical plate, and shelves supported between said air pervious partitions and the opposite sides of said high temperature compartment, and means for circulating a volatile refrigerant through said plates.

HERMAN W. KLEIST.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,439,051 Anderson Dec. 19, 1922 1,758,073 Davenport May 13, 1930 1,775,989 Dennison Sept. 16. 1930 2,085,346 Vretman June 29, 1937 2,117,570 Philipp May 17, 1938 2,156,544 Raskin- May 2, 1939 2,165,505 Philipp July 11, 1939 2,166,506 Philipp July 18, 1939 2,231,013 Kleist Feb. 11, 1941 2,405,482 Kleist Aug. 6, 1946 

